Flanged Bell Mouth

Flanged Bell Mouth is a short straight duct that is spun and formed to produce a bugle mouth. Used as suction hoods.

Collecting air with a hood involves more than just creating a range hood-style apparatus close to the source and hoping that the air will be drawn in. Air behaves as a fluid and therefore has dynamics that work against air in front of the hood being drawn in. A good way to think about this is to visualize pushing a bucket down into a large tub of water. The water flows in over the side even if the bucket is forced down quickly. Likewise, air will come in from the side of a hood before it will enter the face. Adding a perimeter flange can limit this effect as can the addition of baffles.